* [RFC][PATCH 2/14] Convert arm to read/update_persistent_clock
[not found] ` <1261540826.3508.62.camel@localhost.localdomain>
@ 2009-12-23 4:01 ` john stultz
2009-12-24 11:09 ` Uwe Kleine-König
0 siblings, 1 reply; 2+ messages in thread
From: john stultz @ 2009-12-23 4:01 UTC (permalink / raw)
To: linux-arm-kernel
This patch converts the arm architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.
Also removes a direct xtime access, replacing it with
current_kernel_time()
I have not built or tested this patch, so help from arch maintainers
would be appreciated.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
---
Kconfig | 3 +++
include/asm/mach/time.h | 2 +-
kernel/time.c | 39 ++++++++-------------------------------
mach-footbridge/time.c | 4 ++--
4 files changed, 14 insertions(+), 34 deletions(-)
Index: gettimeoffset/arch/arm/Kconfig
===================================================================
--- gettimeoffset.orig/arch/arm/Kconfig 2009-12-22 18:50:54.000000000 -0800
+++ gettimeoffset/arch/arm/Kconfig 2009-12-22 18:51:20.000000000 -0800
@@ -38,6 +38,9 @@ config GENERIC_GPIO
config GENERIC_TIME
bool
+config GENERIC_CMOS_UPDATE
+ def_bool y
+
config GENERIC_CLOCKEVENTS
bool
Index: gettimeoffset/arch/arm/include/asm/mach/time.h
===================================================================
--- gettimeoffset.orig/arch/arm/include/asm/mach/time.h 2009-12-22 18:50:54.000000000 -0800
+++ gettimeoffset/arch/arm/include/asm/mach/time.h 2009-12-22 18:51:20.000000000 -0800
@@ -50,7 +50,7 @@ extern void timer_tick(void);
* Kernel time keeping support.
*/
struct timespec;
-extern int (*set_rtc)(void);
+extern int (*set_rtc)(struct timespec now);
extern void save_time_delta(struct timespec *delta, struct timespec *rtc);
extern void restore_time_delta(struct timespec *delta, struct timespec *rtc);
Index: gettimeoffset/arch/arm/kernel/time.c
===================================================================
--- gettimeoffset.orig/arch/arm/kernel/time.c 2009-12-22 18:50:54.000000000 -0800
+++ gettimeoffset/arch/arm/kernel/time.c 2009-12-22 18:51:20.000000000 -0800
@@ -80,7 +80,7 @@ EXPORT_SYMBOL(profile_pc);
/*
* hook for setting the RTC's idea of the current time.
*/
-int (*set_rtc)(void);
+int (*set_rtc)(struct timespec now);
#ifndef CONFIG_GENERIC_TIME
static unsigned long dummy_gettimeoffset(void)
@@ -89,34 +89,11 @@ static unsigned long dummy_gettimeoffset
}
#endif
-static unsigned long next_rtc_update;
-
-/*
- * If we have an externally synchronized linux clock, then update
- * CMOS clock accordingly every ~11 minutes. set_rtc() has to be
- * called as close as possible to 500 ms before the new second
- * starts.
- */
-static inline void do_set_rtc(void)
+int update_persistent_clock(struct timespec now)
{
- if (!ntp_synced() || set_rtc == NULL)
- return;
-
- if (next_rtc_update &&
- time_before((unsigned long)xtime.tv_sec, next_rtc_update))
- return;
-
- if (xtime.tv_nsec < 500000000 - ((unsigned) tick_nsec >> 1) &&
- xtime.tv_nsec >= 500000000 + ((unsigned) tick_nsec >> 1))
- return;
-
- if (set_rtc())
- /*
- * rtc update failed. Try again in 60s
- */
- next_rtc_update = xtime.tv_sec + 60;
- else
- next_rtc_update = xtime.tv_sec + 660;
+ if (set_rtc == NULL)
+ return -1;
+ return set_rtc(now);
}
#ifdef CONFIG_LEDS
@@ -305,9 +282,10 @@ EXPORT_SYMBOL(do_settimeofday);
*/
void save_time_delta(struct timespec *delta, struct timespec *rtc)
{
+ struct timespec now = current_kernel_time();
set_normalized_timespec(delta,
- xtime.tv_sec - rtc->tv_sec,
- xtime.tv_nsec - rtc->tv_nsec);
+ now.tv_sec - rtc->tv_sec,
+ now.tv_nsec - rtc->tv_nsec);
}
EXPORT_SYMBOL(save_time_delta);
@@ -336,7 +314,6 @@ void timer_tick(void)
{
profile_tick(CPU_PROFILING);
do_leds();
- do_set_rtc();
write_seqlock(&xtime_lock);
do_timer(1);
write_sequnlock(&xtime_lock);
Index: gettimeoffset/arch/arm/mach-footbridge/time.c
===================================================================
--- gettimeoffset.orig/arch/arm/mach-footbridge/time.c 2009-12-22 18:50:54.000000000 -0800
+++ gettimeoffset/arch/arm/mach-footbridge/time.c 2009-12-22 18:51:20.000000000 -0800
@@ -61,12 +61,12 @@ static unsigned long __init get_isa_cmos
return mktime(year, mon, day, hour, min, sec);
}
-static int set_isa_cmos_time(void)
+static int set_isa_cmos_time(struct timespec now)
{
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
unsigned char save_control, save_freq_select;
- unsigned long nowtime = xtime.tv_sec;
+ unsigned long nowtime = now.tv_sec;
save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
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